Nail driver



Dec. 20, 1955 J. G. CAMERON NAIL DRIVER Filed May 14, 1952 INVIENTDKJOHN GKIFFIIWS c/wawu United States Patent This invention relates toimprovements in nail drivers.

It is known to provide manually or mechanically operated nail drivers,such a device commonly including a tubular casing the lower end of whichis adapted to be placed on timber to be nailed, and a plunger slidablein the casing, the plunger being weighted usually by a heavy handle atits upper end in the case of manually operable apparatus, the lower endof the'plunger being provided with a co-axial striker. Nails fed intothe easing, either individually or by means of a magazine, passgravitationally to the lower part of the casing, and are driven into thetimber when the connected plunger and striker are brought forcibly downso that the striker hits the nail head.

It has been found that nail drivers of this character have thedisadvantage that after being used for some time, the end of the strikerwhich impinges on the nail heads quickly becomes burred over, andconsequently it is liable to jam in the part of the casing in which itis mounted, making the nail driver useless until repaired.

My present invention has been devised to overcome the said presentdisadvantages, and it has for its principal object the provision of anail'driver the striker of which is so made and arranged that its endwhich drives 'nails is not liable to become burred over, at least untilit has been in use for a very long time.

Another object of the invention is to provide a nail driver the strikerof which is of the improved character stated and which may be easilyreplaced whenever required.

Further objects of the invention are to provide a nail driver thestriker of which is of the improved character set out, and which issimple and economical to manufacture, efficient in operation, and sturdyand durable in use.

According to my invention, I provide a nail driver which includes aweighted plunger reciprocally slidable in a plunger guide, preferably oftubular form and terminating at its lower end in a tubular nail guide,which may be positioned on the material to be nailed, a striker beingconnected to the plunger so that, when the plunger is raised, thestriker is lifted from the nail guide to enable a nail to. be fedthereinto from a communicating nail passage, and when the plunger isforcibly depressed, the striker is caused to drive the nail through itsguide into the material on which the device has been-placed, a resilientbutfer being interposed between the weighted plunger and the strikersuch that the striker is maintained in extended position in relation tothe plunger until the striker is brought to bear on the head of a nailin the striker guide. The striker, then, remains momentarily at rest onthe nail until, after the buffer has been compressed longitudinally bythe still descending plunger, the force of the plunger is transmitted tothe striker which is caused to drive the nail.

I have found that, whereas a striker fixedly connected to the plungerbecomes burred after a short period of use, the interposition of aresilient buffer betweenthe 1 2,727,235 Patented Dec. 20, 1955 plungerand striker ensures that the end of the striker contacting the nail headdoes not become burred, at least until the device has been used for avery considerable period. In the preferred form of the invention, thebutter consists of a plug of rubber or like resilient material capableof being distorted, but more or less incompressible, enclosed in acavity such that its lateral expansion, and therefore its longitudinalcompression, is

limited; and in this form of the invention, the striker is found to'havea 'very considerable life, not being liable to burr at either end atleast until the device has been used for a very long period.

I prefer that the nail passage be such that an operator may feed nailsthereto at a convenient height while standing, the nails being carriedgravitationally through the passage to the nail guide; and for ease ofoperation of the device, I prefer to provide a foot holder at the lowerend of the nail driver which can be fastened to one foot of the operatorto facilitate the correct positioning of the device on a floor, forexample.

Inorder that my invention may be readily understood and put intopractical effect, I now refer to the accompanying drawings, wherein:

Figure 1 is a side elevational view of a nail driver according to theinvention;

Figure 2 is a broken away sectional view of the nail driver; and 1Figure 3 is a broken away sectional view of a nail driver according to amodification of the invention.

The nail driver includes a casing 10 consisting of a length of metaltube. Screw-threadedly engaged in the lower end portion of the casing 10is a metal nail guide member -11, which is of substantially cylindricalshape with an integral peripheral flange 12, the upper part of the nailguide member above the flange being threaded for engagement in thecasing, the said flange 12 hearing against the bottom of the casing 10.An axial boring 13, the greater part of which is slightly greater indiameter than the heads of nails to be driven, is formed through thenail guide 11, the upper end portion of the said axial bore being flaredat 14 to form a lead-in to the remainder of the bore.

Engaged on the nail guide 11 is a foot holder 15, which includes a strap16 apertured at one end to fit closely about the nail guide below itsflange 12; a metal sleeve 17 fitted closely but rotatably on the nailguide and acting to retain the strap 16 in place; an angle bracket 18secured to or formed integrally with the sleeve 17 and extending fromthe lower part thereof; a foot bracket 19 secured by rivets 20 to thesaid angle bracket; and a foot 21 riveted or otherwise secured to thefoot bracket at one end, and having secured to its other end a buckle 22adapted to engage the strap 16 in desired adjustment. The foot holder 15is retained in place by means of a knurled nut 23 threadedly engaged onthe lower end portion of the nail guide 11. The lower part of the boreof the nut 23 is enlarged and plain to form an annular recess 24, whichhouses portion of an annular resilient pad 25 of rubber, for example,which is fitted closely on the lower end of the nail guide, and extendsdownwardly for some distance below the said nail guide.

There is fitted slidably within the casing 10 a plunger 26, consistingof a metal rod, the upper end portion of which 'is reduced in diameter,screw-threaded and engaged the adjustment nut in desired adjustedposition.

A nail passage 31 is formed longitudinally in the side of the plunger 26from the bottom of the threaded upper portion to the bottom of theplunger. A key 32 secured to and extending inwardly from the upperendportiontof xthe casing 10 engages in the said nail passage to preuenttheplunger 26 from being rotated in relation ito the said casing.

A longitudinal slot-like feedopeningfiS isforme inrthe upper ;part ofthe-casing 10, some distance below .the key 32, and in register withtthe nail passage 31. A mailchute 34 is secured to the casing 10, leadingto the said feed.

opening, and it has secured in its .upper'enda metal gauge ring 35,:thebore of which is aboutequalto the bore 13 of the .nail guide 11, so thatanormalnail to :hGtdIi QI -Wm pass freely therethrough into the chute.34 and through-the feedopening 33 into .the.nail passage 31; but a.nail'the head of which is oversize or badly deformed will not bevablezto-pass throughthesaid gauge ring.

The lower-endof the plunger 26 is axially bored at 36.

Referring now to Figure 2, there is provided ta striker 37, the lowerpart of which is of-such:diametertbat-it-will fit fairly closely butslidably in the boring 1343f zthe nail guide, the striker having anenlarged diameter .hea 3. which is adapted to engage slidably in thebore Of the plunger. There is fitted closely into the upper part of .thesaid bore of the plunger a resilient-cylindrical ;plug ,39 madegfor:preference, of rubber, the head -38- of th e'striker 37 then beingfitted into the said bore. ;An annularrecess 40 is formed .about thestrikerrhead, and a;.,gr ub screw 41 engaged in a tapped radial aperturein the loweqpartof the plunger .26 engages in the said recess, as istclearly shown-in the drawing.

.In. using the nail driver, if it is desired-topuneh .as Well asdrivethenails, the adjustment nut.29 is ,so positioned that when it.rests upon the topof the casing-10,1116 bottom of the striker 37 extendsfor some distanee-below-ghe level of the bottom of the annular pad25,1the:adjnstment;nut being retained in such positionby the lock nut30. A foot, usually-the right foot, .is en eed. ;bylhfiiflflt'ihQldfiBrthe footrresting on the .foot :strapfilandioot-bracketrlflaan the :straps 16 .and'21 being ifirmly buckled-overthe foot. The casing 10 is turned so that nails may conveniently be-fedby one hand, usually the left hand,-through: the gauge ring 35. ofrthechute -34,-and the handleib'kiagrasped by the other hand. The engagedfoot is usedetozpflsition the resilient annular pad 25 overthe positionwhere ta, nail isto-be driven,-and a nail is; fed, point-first,fllrohgh:.the said gauge ring, falling gravitationally throughlhewhute34, the-feed opening 33, and the nailrpassagegi'ahsandathe handle 27israised to lift the plungers26 and the associated striker 37 .so thatthe said striker is-brought elear 10f the nail guide 11, enabling thenail.to fall through the boring 13 of the nail guide so that its-pointrests :on theztimbenw be nailed. The handle 27 with associated :phmger,are then brought forcibly down, and consequently the Striker 37 isdropped onto the nail head and comestorest'mementarily. The plunger,continuing its downward stroke, causes the resilient plug 39 to bebrought downonto the head 38 of the striker 37. The plug can yieldslightly but,

being substantially incompressible, it follows :that :the

force of the descending plunger 26 is then transmittedato the striker 37which drives the nail homeandipunehes: it below the surface of thetimber. A Mentor-example, may be nailed in place in this fashion andsincere foot, positioning the tool, leaves a handfree:for:-'fceding1nails to the device, the driving and punching ofonenail .after another may be carried out very rapidly. Itwill-be-fouud, moreover, that the striker is not liable .to-bewmdburredover at its lower end which drives the. nails,;-,at least'fo'r a veryconsiderable time; and the upper end of the: striker, which is struck bythe resilient pad 39,,-is-als0-not -1iable to become burred. I

I now refer toFigure 3, which shows-a modified 'form of the invention,in which the striker 42 is; for thegreater part of its length, of suchdiameter that it-willfitslidably in the axial boring 13 of the nailguide 11; but near to the top has an integral coaxial head 43, the lowerpart of which fits slidably in the bore 36 of the plunger 26, the upperpart being of somewhat reduced diameter. The striker head 43 isrestrained from leaving the plunger by means of a washer 44 secured tothe bottom of the plunger 26 by screws 45,the central aperture of thewasher being such that the ,lower part of the striker passes freelytherethrough, but of less diameter than that of the 'lower part ot' thestriker head 43. The washer 44 is notched at one side,,as indicated at4,6, the notch registering with the nail passage 31 in the plunger. Thestriker head 43 ,is of less length than the axial bore 36 in the lowerpart of the plunger; and the said head is normally maintained inlowermost position in the said bore by means of a helical compressionspring 47, its upper end bearing against the top of the said bore, itslower end bearingon the peripheral shoulder formed at the change ofdiameter of the striker head.

{litreail driver according to this modification of the invention-isusedin the same .manner as before described. When the handle 27 is beingforcibly brought down to drive and punch .a nail, indicated at 48, thestriker 42 ijsretained in .extended position by the spring 47 until zthestriker contacts -.the head of the nail 48. Thereupon the striker comesmomentarily to rest, until the further :downward movementof the plunger36, compressing the ,spring 47,-,eauses the plunger to strike the top ofthe striker head 4-3-so that the nail 48 is driven and punched.iltwill-ibe found that the lower end of the striker 42 will not becomeburred over for avery considerable period.

-,I-n. e ither;modil icati on otthe invention, the striker and the nailguide :may be interchangeable with others of ,difierentdiameter and borerespectively, to suit different sizes of -nails appropriateadjustmentbeing made also lo the adjustment; nut 29. -I may prefer to make thegauge ring 135 --rem o vable and interchangeable with others of'rlitterem o eshat l ela rn i l. ,A nail driveninclnding a. plungerguide; a plunger ,-r 'eio .e allyr is ab i th pl nge guide; a nail guidepogmeeted tothe plunger guide and adapted to be positioned adjacent tothe material to be nailed; a striker reciprocally slidable through-theguide and connected to theplppgena stop limiting the sliding movement ofthe striker relativeto'the plunger; a nail passage adapted to conduct anail gravitationally into the nail guide when the ,striker is at leastpartly withdrawn therefrom; and a resilient distortable buffer betweenthe striker and the ,plungenadapted to maintain the striker in extendedrelationship to.the-plun ger until on a working stroke of the plungerthe striker is brought momentarily at rest on the head ofthe naiLin-thenail guide, further movement of the plunger-causing the striker to drivethe nail.

2. -A nail driverincluding a plunger guide; a plunger .reciprocally:slidable in the plunger guide; a nail guide connected-t0 the plungerguide and adapted to be positioned adjacent tothe material to be nailed;a striker reeiprocallyslidable,through the nail guide and connected tothe;plunger;arstop limiting the sliding movement of thestrikerzrelativeto the plunger; a nail passage adapted .tO Conduchanaihgravitationally into the nail guide when t.he striker-,is atleastpartly withdrawn therefrom; and a vbuffer of. a-resilient distortahlebut nearly incompressible material interposed between the striker andthe plunger and contained .in arecess adapted to permit a limitedlateral expansion of the buffer.

53. Aflnail guide.includinga tubular plunger guide; a tubular nailguide:secured co-axially to the lower end of the plungerguidepaplungerreciprocally slidable in the plungenguide; said plungerhaving a longitudinal hole in its lower end; a resilient buffer formedof distortable but -nearly incompressible material in. the innermostpart of:saidhtztlepa striker reciprocally slidable through the nail-guidei its-upper-end-being housed inthe said hole; a stop limiting thesliding movement of the striker in the said hole away from the bufier;and a nail passage adapted to conduct a nail gravitationally from aposition near to the top of the plunger guide into the nail guide whenthe striker has been at least partly withdrawn therefrom.

4. A nail driver including a plunger guide; a plunger reciprocallyslidable in the plunger guide; a nail guide connected to the plungerguide and adapted to be positioned adjacent to the material to benailed; a striker reciprocally slidable through the nail guide andconnected to the plunger; a stop limiting the sliding movement of thestriker to the plunger; a nail passage adapted to conduct a nailgravitationally into the nail guide when the striker is at least partlywithdrawn therefrom; and a spring disposed between and in engagementwith the striker and plunger for yieldably urging the striker inextended relationship to the plunger.

5. A nail guide including a tubular plunger guide; a tubular nail guidesecured co-axially to the lower end of the plunger guide; a plungerreciprocally slidable in the plunger guide, said plunger having a hole;a boring in said tubular nail guide; a striker reciprocally slidablethrough the nail guide, its upper end being housed and longitudinallymovable in the said hole; means for retaining the upper end of thestriker in the said hole with limited longitudinal movement relative tothe plunger; a spring in the hole engageable with the plunger andstriker to urge the striker to extended position relative to theplunger; and a nail passage adapted to conduct a nail gravitationallyfrom a position near to the top of the plunger guide into the nail guidewhen the striker has been at least partly withdrawn therefrom.

References Cited in the file of this patent UNITED STATES PATENTS620,426 Danzer Feb. 28, 1899 1,222,129 Palkowski Apr. 10, 1917 1,262,486Hansen Apr. 9, 1918 1,409,419 Signell Mar. 14, 1922 2,587,944 WilliamsMar. 4, 1952 FOREIGN PATENTS 140,641 Austria Feb. 11, 1935 588,189 GreatBritain May 16, 1947

